Process of separating from pig-iron the vanadium contained therein



, 1O furnaces has a content of vanadium amounting liquid slag, for instance a slag having bases which V 45 will undergo combustion to form silicon dioxide of the initial acid slag which contains practically 5 I Patented Jan. 11, 1938 PROCESS OF SEPARATING FROM PIG-IRON THE VANADIUM CONTAINED TI-IEREIN Nicolans Wark, Soureth-Heerlen, Netherlands No Drawing. Application December 5, 1933, Se-

rial No. 701,081. In Germany December 14,

2 Claims. (CI. 75-52) A great part of the ores to be treated in. the in the metal-bath and the vanadium carried blast-furnace contains admixtures of vanadium back into the pig-iron bath with combustion of which in practice are again completely present the silicon into silicon dioxide (5102). Such unin the pig-iron obtained from the furnace. Thus, prepared slag, therefore, can contain only small for instance, the pig-iron obtained from limonite quantities of vanadium in combined condition 5 (minette), contains from 0.10 to 0.25% of vanaand for this reason is unsuitable for recovering dium, depending upon the degree of breaking up the vanadium from the iron. the ores and other conditions of operation, while According to my invention, on the basis of the pig-iron produced from northern ores by blastabove, a strongly basic, well reacting and very to as much as 1%. among other compounds contain sodium or po- My invention has for its object to devise a tassium compounds, is added to the pig-iron that process which permits separating from the pigcontains vanadium, preferably before oxidation iron .the greatest part of the vanadium contained of the vanadium into vanadic acid commences.

therein by way'of the slag, so that the latter may This slag in its liquid condition and its strongly 5 be further worked economically by the known basic condition will be capable of practically process into ierro vanadium or other vanadium fully binding the resulting vanadic acid. This compounds. vanadic acid is drawn ofi after complete oxida- My invention is based on the fact that the tion of the vanadium and theopen-hearthorother course of chemical reactions in metal baths derefining treatment thereupon is continued under- 20 pends to a very large extent upon the thermal, neath a new normal slag. In this manner a physical and chemical properties of their slags fresh slag is obtained which owing to its high and that certain reactions can be carried out at content of vanadium permits of economical comall only underneath quite definite slags. In case mercial separation of this metal from the iron.

the product obtained by reaction is not afforded As bases, besides sodium oxide (NazO) and potas- 25 the possibility of being taken up and bound by sium oxide (K20), also other substances having a strongly reacting, very liquid and properly a similar effect may be used directly, such as composed slag in its state of unstable equilibrium, for instance manganous oxide (MnO). In order it will be exposed to the danger of being carried to avoid formation of unnecessarily large quanback into the bath under the influence of other tities of slag having a relatively small content of components. vanadium-which is due to the fact that the The vanadium contained in the pig-iron, by combustion of the silicon takes place practically reason of its great afifinity for oxygen due to its simultaneously with the combustion of the vaposition in the periodic system, is. strongly subject naduimand in order to prevent any vanadium to oxidation into vanadic acid. This known which has already entered into the slag from 35 process could heretofore not be fully utilized for being carried back into the bath, it is of advanthe separation of the vanadium from pig-iron tage to first subject the pig-iron to a preliminary becausethe other conditions connected with the open-hearth treatment in order to oxidize the binding of the vanadic acid have heretofore been silicon therein underneath a slag rich in silicic left entirely out of consideration. When treatacid and to bind the thus formed silicic acid either 40 ing pig-iron containing vanadium by the openby lime or metallic bases and draw ofi the comhearth process, first vanadicacid (V205) will be pounds so formed. A vanadium recovery treatformed, however, almost simultaneously therement is now carried out underneath the aforemenwith also the silicon contained in the pig-iron tioned basic and very liquid slag after removal (S102). If the slag is inadequately prepared, for all the silicon. If a pig-iron low in silicon is instance if said slag is not very liquid and thus available as initial material due to properly carincapable of bringing about reaction with all rying through the blast-furnace process, the silisuch acid compounds, that is, not sufiiciently and con treatment can be dispensed with and the effectively basic, the bases present in the slag, charge may then with advantage be treated di- 50 such as calcium oxide (CaO), manganous oxide rectly to separate the vanadium. The compo (MnO) and others by reason of their great afilnsition of the pig-iron is further of importance ity for silicic acid will be bound quickly by the in so far as a greater content of manganese in latter, so that the vanadic acid in uncombined the iron during the blasting process will initially 5 5 and unstable condition is reduced by the silicon expedite the formation of a basic and highly liquid slag. The content of manganous oxide (MnO) which determines the basic character and. the degree of liquidity may therefore be furnished directly by the pig-iron or by adding manganese ores or manganese containing slags to the slag.

The separation of vanadium from the pig-iron may be carried out, according to my invention, in a basic converter. It is however possible to place the prepared slag already in the pig-iron mold before the metal is drawn off from the furnace. In this case the vanadium will be oxidized by the oxygen of the air as it runs into the mold, and taken up by the slag. This oxidation of the vanadium may be promoted by supplying a sufficient amount of oxygen in any other way to the pig-iron. In this manner the greater part of the vanadium contained in the pig-iron may be withdrawn therefrom as early as in the pigiron mold and the slag may be enriched to such an. extent with vanadic acid that it can be worked economically. The oxidation of the vanadium in the pig-iron may be effected according to my invention during the operation of drawing the pig-iron off the blast-furnace either by employing a greater height of drop for the stream of pig-iron flowing out of the furnace, or by supplying air enriched with oxygen or steam, or by adding easily reducible ores or oxygen-supplying substances to the pig-iron mold. In every case the oxidation of the vanadium thus arising is expedited by the reaction of the slag with the pigiron and the reaction-product thus formed is quickly bound. In order to attain greatest possible concentration of the vanadium in the slag, care must be taken to prevent dilution of the latter by blast-furnace slag carried with the pig-iron during drawing-off or by slag formed from the lining of the mold.

By the process according to my invention a practically complete separation of the vanadium from the pig-iron is always attained. The slag greatly enriched with vanadium may also be used directly for the working into vanadium or its compounds, as well as for the alloying of metals, such as liquid steel.

I claim:

1. Process of obtaining vanadium from ironores, said process consisting in reducing said iron-ores to pig-iron in a blast furnace, placing the pig-iron thus produced in a basic converter, adding a strongly basic, very liquid and highly reactive slag to the pig-iron before oxidation of the vanadium contained therein by air can occur, removing the slag so prepared from the ironbath after the combustion of said vanadium is completed, and recovering the vanadium from its slag.

2. Process of obtaining vanadium from ironores, said process consisting in reducing said iron-ores to pig-iron in a blast furnace, placing the pig-iron thus produced in a basic converter, adding a strongly basic, very liquid and highly reactive slag, containing as bases metalous oxides, to the pig-iron before oxidation of .the vanadium contained therein by air can occur, remov ing the slag so prepared from the iron-bath after the combustion of said vanadium is completed, and recovering the vanadium fromits slag.

vNICOLAUS WA K. 

